Wireless communication devices such as smart cards typically include an integrated circuit providing both memory and processing functions, have words or pictures printed on them, and control who uses information stored in the integrated circuit and how the information is used. Some smart cards have length and width dimensions corresponding to those of credit cards. The term "smart card", as used herein, is meant to include cards that include microprocessors. Smart cards have many different applications. For example, smart cards can be pre-paid cards used instead of money for making purchases from vending machines, gaming machines, gas stations, car washes, photocopiers, laundry machines, cinemas, fast-food restaurants, retail outlets, or anywhere where cash is used. For example, they are commonly in Europe with public telephones. A timer is used to deduct a balance from the card automatically while a conversation continues. Because the transaction is electronic, the telephone, vending machine, etc. does not need to store cash, so risk of loss due to theft can be reduced. Change does not need to be stored and disbursed, and received payment can be directly wired to a bank. Pre-paid cards can be a form of advertising, because they can have logos or other information printed on them. The user would typically carry the card for weeks before using up the value on the card.
To authenticate a conventional credit card, a telephone call is made to verify the funds are available. Smart cards permit such verification to be performed off-line, thus saving telecommunication charges. Smart cards thus provide an advantage over conventional credit cards. Smart cards can also be used as keys to gain access to restricted areas, such as secure areas of buildings, or to access parking lots.
Radio frequency identification devices (RFIDs) can also be considered smart cards if they include an integrated circuit. RFIDs are described in detail in U.S. patent application Ser. No. 08/705,043, filed Aug. 29, 1996, and incorporated herein by reference. RFIDs comprising integrated circuits may be referred to as intelligent RFIDs or as remote intelligent communication (RIC) devices.
Smart cards will typically comprise a power source, such as a battery, and an integrated circuit, typically provided as a monolithic chip. The smart card will also typically comprise electrical interconnects for connecting the battery to the IC chip, and, in some applications, for connecting the IC chip to terminals which are external of the card. In other instances, the electronic interconnects will comprise an antenna, such as, for example, when the integrated circuit comprises radio frequency identification device circuitry. As smart cards are intended to be conveniently carried by persons, it is desirable to produce smart cards which are relatively thin, preferably having a size and shape similar to credit cards. This enables the cards to be carried on a person, such as, for example, in a person's wallet.
This invention arose out of concerns associated with providing wireless communication devices which are desirably dimensioned to be carried by or on a person. This invention also arose out of concerns with providing wireless communication devices such as smart cards which are formed from material which does not degrade the electrical performance thereof.